The latest firmware build (17.1.2.A.0.314) for the Xperia Z2 Tablet has now started to roll for the LTE variant of the tablet (SGP521). The same update was released for the Xperia Z2 recently bringing improved touch performance and charging when the battery is low. We should see similar improvements for the Xperia Z2 Tablet, however Sony has not yet updated its support pages with the new changelog.
There’s no word of the update rolling for the Wi-Fi variants of the Xperia Z2 Tablet (SGP511, SGP512), but we’ll keep you posted.
Thanks Faruk!